1. Field of the Invention
This invention relates generally to surgery and post-surgical care, and in particular, provides methods and devices which avoid the formation of adhesions between internal organs and tissues, particularly after surgery.
Post-operative adhesion formation is a major clinical problem after many abdominal, pelvic, thoracic, and other surgical procedures. As the body heals from the trauma of surgery, blood components surround the injured tissue to close the wound. Specifically, free white blood cells and platelets arrange themselves into a regular mesh structure called fibrin. Fibrin promotes healing by knitting traumatized tissues together to close wounds. Tissue then grows on this fibrin substrate.
Unfortunately, fibrin often extends between adjacent tissues at the surgical site. Tough fibrous bands of scar tissue, called "adhesions," may form between organs and tissue layers which normally slide with respect to each other. These bands can lock such tissues in a fixed relative position, causing considerable pain and other morbidity as they pull internally.
Once adhesions are formed, the affected tissues are normally separated through further surgery using sharp dissection. Unfortunately, this follow-on surgery can cause further bleeding, which promotes formation of still further adhesions.
It has recently been proposed to introduce an air cushion-like structure to maintain mechanical separation for prevention of post-operative adhesion formation. While maintaining such mechanical separation can prevent adhesion formation between the tissues which are held apart, such a procedure involves continuously displacing tissues from a time period between a few hours and several days. Such prolonged tissue displacement may itself cause considerable pain, and may be detrimental to the healing process. Additionally, only those tissues which are held apart by the air cushion device will be affected, and fibrin may form between the air cushion device and the surrounding tissues, potentially leading to the formation of adhesions which lock the air cushion in place. Such adhesions would complicate removal of the air cushion, and would increase the probability that bleeding and additional adhesion formation will occur after the device is removed.
An alternative mechanism to prevent the formation of adhesions is to separate the tissues with a thin film of bio-active anti-adhesion material. These anti-adhesion materials may be bio-absorbable, avoiding any post-operative follow-up surgery, or they may be permanent. Anti-adhesion materials have been approved by the Food and Drug Administration and are commercially available under the trade names Interceed.RTM. and Seprafilm.RTM., which have been shown to be effective. Nonetheless, these materials may produce allergic reactions in some patients. White cells and platelets can also migrate to the edges of these films, resulting in adhesion formation despite the presence of the anti-adhesion material. Additionally, deployment of these thin films may be problematic in certain procedures, particularly when using minimally invasive surgical techniques, and subsequent movement of these films from the target area may leave tissues unprotected.
In light of the above, it would be desirable to provide improved methods and systems for the prevention of adhesion formation. It would be preferable if such systems and methods were adaptable for patients who are intolerant to known anti-adhesion materials. It would also be preferable if such improved techniques minimized discomfort for recovering patients, thereby promoting the post-operative healing process.
2. Description of the Background Art
U.S. Pat. No. 5,387,244 describes an adhesion prophylaxis which maintains mechanical separation using an air cushion-like device. Anti-adhesion materials are commercially available from Ethicon of Somerville, N.J., under the trademark Interceed.RTM., and from Genzyme of Cambridge, Mass. under the trademark Seprafilm.RTM..
U.S. Pat. No. 5,120,322 describes a method and apparatus for treatment of fibrotic lesions using lathyrgenic agents. Russian Patent No. 2021776 describes a procedure for preventing post-operation hematoma and muscle/bone adhesions using a silicon tube with an antiseptic filled balloon.
French Patent No. 2673110 describes a balloon-tipped catheter designed to be inflated to hold a catheter in position after insertion. U.S. Pat. Nos. 5,425,760 and 4,800,901 describe balloon-type tissue expansion devices. European Patent No. 461474 describes a catheter with a balloon at its distal end having a spring elastic sleeve which is automatically retractable on balloon deflation.
U.S. Pat. No. 5,192,296 describes a dilation catheter, while U.S. Pat. No. 5,366,472 describes a dilation balloon within an elastic sleeve. U.S. Pat. Nos. 5,290,247 and 5,458,572 are generally relevant.